甲苯储罐区的火灾爆炸危险性分析及防火防爆设计

甲苯（C7H8）是重要的基本有机化工原料，具有亚急性和慢性毒性、易燃，其蒸气与空气可形成爆炸性混合物。遇明火、高热能引起燃烧爆炸。与氧化剂能发生强烈反应。流速过快，容易产生和积聚静电。其蒸气比空气重，能在较低处扩散到相当远的地方，遇明火会引着回燃。由于甲苯的易燃性及其蒸气与空气在一定浓度区间内混合物的爆炸性，因此，如何安全、有效地储存和使用是非常重要的。     

二硫化碳的制造

二硫化碳是一种无色的极易揮发的液体,純粹的略微具有似醚的臭味和辛辣的滋味,不純的含有硫和硫化氫等杂质而呈黄色,并带有臭味。冰点-111.6℃(760毫米)。沸点46.25℃(760毫米)。蒸气压297.5毫米(20℃)。比重1.2661(20℃)。比热0.24卡/克。稍能溶于水,0.201%(20℃)。二硫化碳极易燃燒,空气中含量超过0.063克/升以上,就有发火的可能。它的发火点究竟是多少,取决于二硫化碳存在的条件,而且有很大幅度。在一般情况下,濃度很高的蒸气在有足够的空气的条件下,則在它的沸点温度以上时卽能发火燃燒,濃度漸低則发火点亦漸增高,但由于它具有极高的蒸气压,在平常溫度下,卽有大量形成蒸气的趋向,那就具备引起发火的可能。二硫化碳蒸气与空气按比例混合就有引起爆炸的可能。在1分子二硫化碳与6分子氧的此例下,則能产生每秒钟2640米的高速度爆炸。在与氧气混合条件下,强烈光綫的照射,金属碰撞和其他催化剂更能引起     

知识窗

液化石油气液化石油气又名压凝汽油,是无色气体或黄棕色油状液体,有特殊臭味。与空气混合能形成爆炸性混合物,遇明火、高热极易燃烧爆炸;与氟、氯等能发生剧烈的化学反应。其蒸气比空气重,能在较低处扩散到相当远的地方,遇火源引着回燃;若遇高热,容器内压增大,有开裂和爆炸的危     

液化石油气

液化石油气又名压凝汽油，是无色气体或黄棕色油状液体，有特殊臭味。与空气混合能形成爆炸性混合物，遇明火、高热极易燃烧爆炸；与氟、氯等能发生剧烈的化学反应。其蒸气比空气重，能在较低处扩散到相当远的地方，遇火源引着回燃，若遇高热，容器内压增大，有开裂和爆炸的危险。     

天然气和硫磺非催化反应制二硫化碳100吨/年试验技术总结

一、前言二硫化碳是一种重要的化工原料,它在人造纤维、农药、橡胶、冶金选矿等工业部门有广泛的用途。二硫化碳是无色、易挥发、易燃的液体,在空气中的爆炸范围为1.25到50(体积比)。闪点是-30℃,在100℃自燃。沸点在1大气压下为46.25℃,在4.42大气压下升高到100℃。液态时密度为1.2559克/毫升(25℃)。蒸气密度比空气重2.62倍。二硫化碳微溶于水,它是很多有机化合物的优良溶剂。     

河南驻马店两车相撞 40吨甲醇泄漏

2008年10月8日8时40分许，河南省驻马店市一辆装载量为40t的甲醇槽车在市中华路与蓝天大道交叉口处被运沙车撞中尾部，造成大量甲醇泄漏，剌鼻的甲醇气体迅速向四周扩散。距泄漏点东侧5m处是一早餐点，有3个煤火炉，15m处是1个加油站，路西侧是一化工厂。由于甲醇是无色澄清易燃液体，低毒，有刺激性气味，闪点只有11℃，而爆炸极限却很大，为5．5％一44％，遇明火、高温、氧化剂极易燃烧。当时，天气晴朗，微风偏南，甲醇液体蒸发很快，一旦甲醇液体及蒸气遇明火发生燃烧和爆炸，后果不堪设想，情形万分危急。     

可燃物质的爆炸极限数据

有机化合物除卤化物等少数物质外,几乎所有的其他物质均是可燃性的。这些物质与空气接触时,其蒸气能与氧化合而发生燃烧反应,同时要放出大量的热能。人们正是利用这种可燃烧的特性,将某些化合物作为工业和民用能源。然而,这些物质的蒸气与空气混合,当浓度在一定范围内时又会遇火爆炸。这种引起爆炸燃烧的极限浓度称为爆炸极限。在爆炸上、下极限浓度以外的操作是安全的。在化工生产中,可燃物质的制造、运输、使用、贮存等任何一个过程中的不慎     

二硫化碳安全使用浅析

二硫化碳作为一种常用化学原料,在精细化工行业中广泛使用,用途很广,但它的危险特性却不容忽视,此种化学物质属于第3类易燃液体、第1项低闪点液体,是易燃易爆、易中毒的物质,其气体极易燃烧和爆炸,来自任何电闸开关、铁器碰撞、静电等的火花,或其他高热如蒸汽管道、高温物体表面等均能引起其燃烧爆炸。本文仅对二硫化碳的易燃易爆的危险性及其防范措施,怎样才能做到安全使用,作一个浅显的探讨。     

石油天然气站场总平面布置对蒸汽云爆炸的防范措施

蒸气云爆炸(VCE:VAPOR CLOUD EXPLOSION)是石油企业中常见的爆炸形式,一般起因于轻烃或其它可燃物质的泄漏,可燃气体与空气混合形成爆炸性蒸气云,在生产设备紧凑布置的拥挤空间内,遇明火后由爆燃(火焰阵面以亚音速推进)发展为爆轰(火焰阵面以超音速推进),形成蒸气云爆炸。在以往的石油天然气站场总图设计中,多数情况下安全距离的设置只考虑防火安全距离的要求,对于防爆没有可以执行的明确规定,在实际生产中发生多起蒸汽云爆炸事故,造成重大人员伤亡和财产损失。本文通过对蒸汽云爆炸进行计算分析,对石油天然气站场总平面布置对蒸汽云爆炸事故防范措施进行研究。     

尿素合成塔液相泄漏蒸气爆炸压力计算

基于热力学理论,对尿素合成塔液相区泄漏的蒸气爆炸进行了理论计算。将裂纹型缺陷作为泄漏口,并且认为裂纹张开面积随内部压力载荷的变化而变化,从而对泄漏速率产生影响,进而影响内部爆炸压力载荷的反弹。计算结果表明:盛装高温、高压物料的尿素合成塔的液相区泄漏能够引发蒸气爆炸。     

含硫油品储罐硫铁化合物自然氧化影响因素考察

含硫原油储罐中的活性硫(硫化氢、硫、硫醇)与罐内壁腐蚀产物铁的氧化反应生成不同形式的硫铁化合物(FeS、Fe2S3、FeS2、Fe3S4)。这些化合物活性很高,与空气中的氧气反应放出大量的热,使储罐内温度升高,导致燃点低的物质发生自燃,从而引起火灾事故。在不同环境温度下模拟了含硫油品储罐铁的硫化物的生成,并在同一氧气流速下考察了硫铁化合物生成时环境温度对其自然氧化倾向性的影响,同时考察了铁锈水分含量对其硫化产物自然氧化倾向性的影响。结果表明,制备时环境温度不同、硫化产物的主要成分不同;制备时环境温度越高、铁锈水分含量越高,硫铁化合物的自然氧化倾向性就越高。     

Theoretical Prediction of Pressure and Temperature of an Aluminized High Explosive in Underwater Explosion

The blast wave propagation in underwater explosion was studied. The shock propagation in water medium was different from that in air. The blast effect in water lasted longer and offered resistance to the expansion of hot gases and release of energy. A theoretical analysis of the expansion of blast wave in water was carried out and numerical results for pressures and temperatures were obtained as functions of distance and time by analytically solving the governing equations. The initial peak pressures of blast waves, which were required for theoretical analysis were calculated using the blast wave theory. Underwater blasts with different weights (0.045, 0.5, and 1.0 kg) of the aluminized high explosive HBX‐3 were conducted to record pressure as a function of distance and time from the blast point. Theoretical results were compared with experimental data and empirical data for HBX‐3 from literature. Since the measurement of pressure and temperature at close proximity of point of detonation is difficult, theoretical modeling of underwater blast is of significant importance.     

Theoretical and Experimental Studies on Blast Wave Propagation in Air

High pressure and temperature are produced when high explosives are detonated in open air. The heat of detonation of the explosive compound, peak pressure, and temperature of the blast wave are important blast parameters. A blast wave generated due to explosion propagates into the air medium at supersonic speed until the pressure in the blast zone is released completely. The intensity of the impact by the blast wave on any intervening solid object depends on the blast parameters and the speed of propagation of the blast wave. A theoretical analysis is carried out to predict the pressure produced in the expanding blast zone as function of distance and time by analytically solving the governing equations. The initial peak pressure and temperature of blast wave, which are required in the theoretical analysis, were calculated making use of the blast wave theory. For comparison, experiments were conducted by detonating different weights of high explosives, and pressures were recorded at various distances from the blast point. The high explosives used in the experiments were TNT (0.045, 0.5, 1, 15, and 40 kg) and Composition B (0.045, 0.5, 1, and 15 kg). The theoretical results are validated by comparison with the experimental data and empirical equations available in literature.     

Assessment of fire protection performance of water mist applied in exhaust ducts for semiconductor fabrication process

Fume exhaust pipes used in semiconductor facilities underwent a series of fire tests to evaluate the performance of a water mist system. The parameters considered were the amount of water that the mist nozzles used, the air flow velocity, the fire intensity and the water mist system operating pressure. In order to make a performance comparison, tests were also performed with a standard sprinkler system. The base case served as a reference and applied a single water mist nozzle (100 bar operating pressure, 7.3 l/min water volume flux and 200 µm mean droplet size) installed in the pipe (60 cm in diameter) subjected to a 350°C air flow with an average velocity of 2 m/s. In such a case, the temperature in the hot flow dropped sharply as the water mist nozzle was activated and reached a 60°C saturation point. Under the same operating conditions, four mist nozzles were applied, and made no further contribution to reducing the fire temperature compared with the case using only a single nozzle. Similar fire protection performances to that in the base case were still retained when the exhaust flow velocity increased to 3 m/s and the inlet air temperature was increased to 500°C due to a stronger input fire scenario, respectively. Changing to a water mist system produced a better performance than a standard sprinkler. With regard to the effect of operating pressure of water mist system, a higher operating pressure can have a better performance. The results above indicate that the droplet size in a water‐related fire protection system plays a critical role. Copyright © 2005 John Wiley & Sons, Ltd.     

Maximum explosive pressure and temperature of vapor-air mixtures

For mixtures of air with highly inflammable vapor, the maximum explosive pressure corresponds to superstoichiometric fuel concentrations. The maximum explosive pressure is similar for different classes of compounds and considerably exceeds the handbook values. This must be taken into account in predicting the consequences of explosions.     

Shock Profiles Along a Specimen

The observation of shock waves in a block of plexiglass caused by a detonating high explosive charge shows the influence of air-gaps and cover-plates which are attached head on. The shock wave for high explosive charges without any cover plate gives a high maximum pressure which decays quickly. The detonating high explosive charge which is covered with a two millimeter thick disc of copper shows a shock wave which is constant over a certain time. An air-gap between the high explosive charge and the measuring plexiglass block always gives a weak shockwave at the beginning. In the case of an uncovered high explosive charge the expansion of the high explosive products gives a relatively smooth increasing blast or shock wave, and in the case of a covered high explosive charge a strong shock resulting from the following impact of the flying plate.     

应用二维黏性CE/SE方法模拟挡波墙对爆炸流场的影响

应用高精度的二维黏性CE/SE方法模拟爆点周围有挡波墙的爆炸流场,分析了挡波墙与冲击波相互作用的规律,得到了能够反映波系结构变化的压力等值线图.数值计算结果显示了冲击波遇挡波墙发生反射、绕流等现象;通过与无挡波墙时的爆炸流场对比,分析了挡波墙的削波作用;同时考察了挡波墙的高度、厚度对远场压力的影响.数值计算结果对于爆炸流场的防护具有理论指导意义.     

基于顶盖举起试验的炸药内爆炸性能评估

为了评估炸药在密闭/半密闭结构内的爆炸性能,通过自建的顶盖举起试验装置对5种典型炸药装药进行了内爆炸试验,利用冲击波超压和顶盖的举起位移评估了其内爆炸威力。结果表明,冲击波超压高的炸药,内爆炸性能不一定好,炸药的空中爆炸性能与内爆炸性能具有显著的差异;顶盖举起最大位移与炸药的非同步自氧化燃烧热具有线性关系,关系式为xmax=17.717ΔHas-5.322,相关系数R2=0.991 7;内爆类炸药应具有高燃烧热、高非同步自氧化燃烧热和适中的爆速。     

Experimental discussion on the mechanisms behind the fire spalling of concrete

The behaviour of six concretes at high temperature (600 °C) and in particular the risk of fire spalling is studied. Tests are performed with two sizes of samples: small samples (300 × 300 × 120 mm³) and small slabs (700 × 600 × 150 mm³). Different storage conditions (pre‐drying at 80 °C, air and water storing) are used to highlight the effect of the initial water content. Thanks to different scenarios of heating, the influence of the heating curve is studied. Results enabled to identify parameters that highly influence the risk of fire spalling: initial water content and concrete permeability during heating. The permeability of concrete can increase during heating due to the melting of the polypropylene fibres or by thermal damage. This thermal damage is important when heating is violent (ISO 834 or increased hydrocarbon fire), or when concrete is made with silico‐calcareous aggregates (flint). Fire spalling cannot be explained by either the only thermo‐mechanical behaviour of concrete, or only by the appearance of high pore gas pressure. Based on the recent hypothesis of the critical zone, the formation of a saturated layer of liquid water is consistent with the results obtained. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect of simulated combustion atmospheres on oxidation and microstructure evolution of aluminum alloy 5052

Among the common materials, metals can be hardly destroyed by flame or the heat emanating from a normal fire. Consequently, investigation on the thermal patterns produced on metallic objects after fire exposure can provide important physical evidence for fire cause/origin determination. Aluminum alloy is widely used in our daily life and the industry; hence, it can be easily found on a domestic or industrial fire scene. In this paper, the aluminum alloy 5052 was exposed in the simulated combustion gases with and without kerosene in the range of 300 to 500°C. Mass change, morphologies, and microstructures of each sample were carefully characterized by thermogravimetric analysis, morphologic observation, and electron microscopy observation with energy‐dispersive spectroscopy analysis after exposure. As expected, the microstructure of alloy changed during high temperature exposure. At the same time, an oxide scale formed and was thickened on the surface of alloy. The results reveal that the temperature can significantly affect the growth of oxide scale and the metallurgical microstructure of alloy. It is noteworthy that the presence of kerosene in the combustion gas accelerated oxidation rate and produced oxide scales different from those formed in air. These feature evolutions in surface oxide are expected to offer complementary insight on determining the fire characteristics, such as the exposure temperature, period and whether liquid accelerant is involved.